안드로이드 TODOLIST 만들기 (feat. SQL OpenHelper)

 

 

데이터베이스 class

package com.gohool.sqiteexample;

import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

import androidx.annotation.Nullable;

import java.util.ArrayList;

//데이터베이스
public class DBHelper extends SQLiteOpenHelper {


    //버전
    private static final int DB_VERSION = 1;
    //db이름
    private static final String DB_NAME = "dw.db";

    //생성자
    public DBHelper(@Nullable Context context) {
        super(context,DB_NAME,null,DB_VERSION);
    }



    @Override
    public void onCreate(SQLiteDatabase db) { //데이터베이스가 생성됐을때 호출/ AUTOINCREMENT: 하나하나씩 값이 올라감 id++
        // 데이터베이스 -> 테이블 -> 컬럼 -> 값
        db.execSQL("CREATE TABLE IF NOT EXISTS ToDoList (id INTEGER PRIMARY KEY AUTOINCREMENT, title TEXT NOT NULL, content TEXT NOT NULL, writeDate TEXT NOT NULL)");
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

        onCreate(db);
    }

    //SELECT문 (조회)
    public ArrayList<ToDoItem> getToDoList() { //ArrayList<ToDoItem>데이터형식의 메소드
      ArrayList<ToDoItem> toDoItems = new ArrayList<>();

      SQLiteDatabase db = getReadableDatabase();
      Cursor cursor = db.rawQuery("SELECT * FROM ToDoList ORDER BY writeDate DESC", null); //cursor : 가르키다
      if(cursor.getCount() != 0) { //데이터가 있으면
          while (cursor.moveToNext()){ //다음 데이터가 없을때까지
              int id = cursor.getInt(cursor.getColumnIndex("id")); //cursor가 가르켜 가져옴 / 데이터를 변수에 넣어줄거임
              String title = cursor.getString(cursor.getColumnIndex("title"));
              String content = cursor.getString(cursor.getColumnIndex("content"));
              String writeDate = cursor.getString(cursor.getColumnIndex("writeDate"));


              ToDoItem toDoItem = new ToDoItem();
              toDoItem.setId(id);
              toDoItem.setTitle(title);
              toDoItem.setContent(content);
              toDoItem.setWriteDate(writeDate);
              toDoItems.add(toDoItem); // 리스트에 추가해줌


          }
      }
      cursor.close(); //종료
      return  toDoItems;
    }


    // INSERT문 (삽입) / id값 넣지않음 알아서 입력됨 /
    public void InsertTodo(String _title, String _content, String _writeDate){
        SQLiteDatabase db = getWritableDatabase(); // 쓰기가능
        db.execSQL("INSERT INTO ToDoList (title, content, writeDate) VALUES('" + _title + "', '" + _content + "' , '" + _writeDate + "');"); // sql문
    }

    //UPDATE 문(수정)
    public void UpdateToDo(String _title, String _content, String _writeDate, String _beforeDate){
        SQLiteDatabase db = getWritableDatabase();
        db.execSQL("UPDATE ToDoList SET title= '" + _title + "', content = '" + _content + "',  writeDate = '" + _writeDate + "' WHERE writeDate= '" + _beforeDate + "'");
    }

    //DELETE 문(삭제)
    public void DeleteToDo(String _beforeDate){
        SQLiteDatabase db = getWritableDatabase();
        db.execSQL("DELETE FROM ToDoList WHERE writeDate = '" + _beforeDate + "' "); //id만 지우면 됨
    }

}

gradle

dependencies {

    implementation 'androidx.appcompat:appcompat:1.2.0'
    implementation 'com.google.android.material:material:1.2.1'
    implementation 'androidx.constraintlayout:constraintlayout:2.0.4'
    implementation 'com.google.android.material:material:1.2.1'
    testImplementation 'junit:junit:4.+'
    androidTestImplementation 'androidx.test.ext:junit:1.1.2'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'
}

android.defaultConfig.vectorDrawables.useSupportLibrary = true

 

사용할 아이템들 class

 

package com.gohool.sqiteexample;

public class ToDoItem {
    private int id;
    private String title;
    private String content;
    private String writeDate;

    public ToDoItem() {
    }


    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getContent() {
        return content;
    }

    public void setContent(String content) {
        this.content = content;
    }

    public String getWriteDate() {
        return writeDate;
    }

    public void setWriteDate(String writeDate) {
        this.writeDate = writeDate;
    }
}

manifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.gohool.sqiteexample">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.AppCompat.Light.NoActionBar"> //테마
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

팝업창 xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="300dp"
        android:layout_marginStart="32dp"
        android:layout_marginTop="32dp"
        android:layout_marginEnd="32dp"
        android:layout_marginBottom="32dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <TextView
            android:id="@+id/dialog_title"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="16dp"
            android:layout_marginTop="16dp"
            android:text="게시글 제목"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />

        <!-- singleLines, maxLines : 초과입력시에도 한줄로 고정 -->

        <TextView
            android:id="@+id/dialog_content"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="16dp"
            android:layout_marginTop="16dp"
            android:text="게시글 내용"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/edit_title" />

        <EditText
            android:id="@+id/edit_title"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="8dp"
            android:ems="10"
            android:inputType="textPersonName"
            android:maxLines="1"
            android:singleLine="true"
            app:layout_constraintStart_toStartOf="@+id/dialog_title"
            app:layout_constraintTop_toBottomOf="@+id/dialog_title" />

        <EditText
            android:id="@+id/edit_content"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="8dp"
            android:ems="10"
            android:inputType="textPersonName"
            android:maxLines="1"
            android:singleLine="true"
            app:layout_constraintStart_toStartOf="@+id/dialog_content"
            app:layout_constraintTop_toBottomOf="@+id/dialog_content" />

        <Button
            android:id="@+id/dialog_btn"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginStart="16dp"
            android:layout_marginEnd="16dp"
            android:layout_marginBottom="8dp"
            android:background="@color/design_default_color_secondary"
            android:text="확인"
            android:textColor="@color/white"
            android:textSize="18sp"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent" />

    </androidx.constraintlayout.widget.ConstraintLayout>
</androidx.constraintlayout.widget.ConstraintLayout>

itemlist.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <TextView
        android:id="@+id/tv_title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginTop="8dp"
        android:text="제목"
        android:textColor="#070505"
        android:textSize="24dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/tv_content"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:layout_marginBottom="8dp"
        android:text="내용"
        android:textColor="#070505"
        android:textSize="20dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="@+id/tv_title"
        app:layout_constraintTop_toBottomOf="@+id/tv_title" />

    <TextView
        android:id="@+id/tv_date"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="16dp"
        android:text="작성날짜"
        android:textColor="#070505"
        android:textSize="16dp"
        app:layout_constraintBottom_toBottomOf="@+id/tv_content"
        app:layout_constraintEnd_toEndOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

activitymain. xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <com.google.android.material.floatingactionbutton.FloatingActionButton
        android:id="@+id/add_btn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="25dp"
        android:layout_marginBottom="25dp"
        android:clickable="true"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:srcCompat="@drawable/ic_baseline_add_circle_outline_24" />

        <!--app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"

        tools:listitem="@layout/item_list" : 미리보기
        -->

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/re_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginStart="16dp"
        android:layout_marginTop="16dp"
        android:layout_marginEnd="16dp"
        android:layout_marginBottom="16dp"
        tools:listitem="@layout/item_list"
        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

CustomAdapter . class

 

package com.gohool.sqiteexample;

import android.app.AlertDialog;
import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;

public class CustomAdapter extends RecyclerView.Adapter<CustomAdapter.ViewHolder> {

    private ArrayList<ToDoItem> mToDoItems; // m:전역변수
    private Context mcontext;
    private DBHelper mDBhelper;

    public CustomAdapter(ArrayList<ToDoItem> mToDoItems, Context mcontext) {
        this.mToDoItems = mToDoItems;
        this.mcontext = mcontext;
        mDBhelper = new DBHelper(mcontext); //

    }

    @NonNull
    @Override
    public CustomAdapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View holder = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_list, parent, false);

        return new ViewHolder(holder);
    }

    @Override
    public void onBindViewHolder(@NonNull CustomAdapter.ViewHolder holder, int position) {

        holder.tv_title.setText(mToDoItems.get(position).getTitle());
        holder.tv_content.setText(mToDoItems.get(position).getContent());
        holder.tv_date.setText(mToDoItems.get(position).getWriteDate());

    }

    @Override
    public int getItemCount() {
        return mToDoItems.size();
    }

    public class ViewHolder extends RecyclerView.ViewHolder {

        //item_list.xml
        private TextView tv_title;
        private TextView tv_content;
        private TextView tv_date;

        public ViewHolder(@NonNull View itemView) {
            super(itemView);

            tv_title = (TextView) itemView.findViewById(R.id.tv_title);
            tv_content = (TextView) itemView.findViewById(R.id.tv_content);
            tv_date = (TextView) itemView.findViewById(R.id.tv_date);


            itemView.setOnClickListener(new View.OnClickListener() { //객체 하나
                @Override
                public void onClick(View v) {
                    int curPos = getAdapterPosition(); //클릭한  위치값 가져오기
                    ToDoItem toDoItem = mToDoItems.get(curPos);


                    String[] strChoiceItems = {"수정하기", "삭제하기"}; //0, 1
                    AlertDialog.Builder builder = new AlertDialog.Builder(mcontext);
                    builder.setTitle("원하는 작업을 선택해주세요");
                    builder.setItems(strChoiceItems, new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialogInterface, int position) {
                            if(position == 0) { //수정하기 / 팝업창
                                Dialog dialog = new Dialog(mcontext, android.R.style.Theme_Material_Light_Dialog); //팝업창
                                dialog.setContentView(R.layout.dialog_edit);
                                EditText edit_title = dialog.findViewById(R.id.edit_title);
                                EditText edit_content = dialog.findViewById(R.id.edit_content);
                                Button dialog_btn = dialog.findViewById(R.id.dialog_btn);

                                edit_title.setText(toDoItem.getTitle()); //수정시 내용 가져오기
                                edit_content.setText(toDoItem.getContent());

                                edit_title.setSelection(edit_title.getText().length()); //수정시 커서 마지막에 놓기


                                dialog_btn.setOnClickListener(new View.OnClickListener() {
                                    @Override
                                    public void onClick(View v) {
                                        //db 업데이트
                                        String title = edit_title.getText().toString();
                                        String content = edit_content.getText().toString();
                                        String currentTime = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()); //현재시간 받아오기
                                        String beforeTime = toDoItem.getWriteDate(); //등록되었던 시간

                                        mDBhelper.UpdateToDo(title, content,currentTime,beforeTime); //db에 넣기

                                        //UI 업데이트
                                        toDoItem.setTitle(title);;
                                        toDoItem.setContent(content);
                                        toDoItem.setWriteDate(currentTime);
                                        notifyItemChanged(curPos, toDoItem); //현재 객체, 갱신
                                        dialog.dismiss(); //끔
                                        Toast.makeText(mcontext, "수정이 완료 되었습니다.", Toast.LENGTH_SHORT).show();
                                    }
                                });
                                dialog.show(); //필수

                            } else if(position == 1){ //삭제하기
                                // db 테이블 삭제
                                String beforeTime = toDoItem.getWriteDate(); //등록되었던 시간
                                mDBhelper.DeleteToDo(beforeTime);
                                //UI 삭제
                                mToDoItems.remove(curPos);
                                notifyItemRemoved(curPos);
                                Toast.makeText(mcontext, "삭제가 완료되었습니다.", Toast.LENGTH_SHORT).show();


                            }
                        }
                    });
                    builder.show();
                }
            });
        }
    }
    // 액티비티에서 호출되는 함수이며, 현재 어댑터에 새로운 게시글 아이템을 전달받아 추가하는 목적
    public void addItem(ToDoItem _item){
        mToDoItems.add(0, _item); // 0번째에 추가됨
        notifyItemInserted(0); //새로고침
    }

}

mainactivity , java

package com.gohool.sqiteexample;

import android.app.Dialog;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.RecyclerView;

import com.google.android.material.floatingactionbutton.FloatingActionButton;

import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;

public class MainActivity extends AppCompatActivity {

    private RecyclerView mrecyclerView;
    private FloatingActionButton madd_btn;
    private ArrayList<ToDoItem> mtoDoItems;
    private DBHelper mdbHelper;
    private CustomAdapter mAdapter;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        setInit();

    }

    private void setInit() {
        mdbHelper = new DBHelper(this);
        mrecyclerView = findViewById(R.id.re_view);
        madd_btn = findViewById(R.id.add_btn);
        mtoDoItems = new ArrayList<>();

        loadRecentDB(); //실행시, 이전에 DB가 존재한다면 LOAD해옴


        madd_btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Dialog dialog = new Dialog(MainActivity.this, android.R.style.Theme_Material_Light_Dialog); //팝업창
                dialog.setContentView(R.layout.dialog_edit);

                //팝업창 정의
                EditText edit_title = dialog.findViewById(R.id.edit_title);
                EditText edit_content = dialog.findViewById(R.id.edit_content);
                Button dialog_btn = dialog.findViewById(R.id.dialog_btn);
                dialog_btn.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        //데이터베이스에 삽입
                        String currentTime = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()); //현재시간 받아오기
                        mdbHelper.InsertTodo(edit_title.getText().toString(), edit_content.getText().toString(),currentTime); //db에 넣기

                        //UI에 삽입
                        ToDoItem item = new ToDoItem();
                        item.setTitle(edit_title.getText().toString());
                        item.setContent(edit_content.getText().toString());
                        item.setWriteDate(currentTime);

                        mAdapter.addItem(item); //객체를 넘겨줌(한 세트)
                        mrecyclerView.smoothScrollToPosition(0); //데이터가 올라갈때마다 ListView가 쫒아올라가서 이쁘게 해줌
                        dialog.dismiss();
                        Toast.makeText(MainActivity.this, "정상적으로 추가되었습니다.", Toast.LENGTH_SHORT).show();



                    }
                });
                dialog.show(); //필수

            }
        });

    }

    private void loadRecentDB() {
        //저장된 db가져옴
        mtoDoItems = mdbHelper.getToDoList();
        if(mAdapter == null){
            mAdapter = new CustomAdapter(mtoDoItems, this);
            mrecyclerView.setHasFixedSize(true); //성능 강화
            mrecyclerView.setAdapter(mAdapter);
        }
    }
}